This report summarizes the preliminery tests of valveless pulsejet engines for application as helicopter tip mounted power plants. These tests were conducted with 4 inch diameter and 5-1/2 inch diameter engines on the Cornell Aeronautical laboratory 10-foot rotor whirling arm test stand at tip speeds up to 600 fps. Major emphasis has been placed upon evaluating the effect of exhaust to inlet area ratio and fuel injecion system upon engine performance and stability over the test speed range. These tests have indicated that stable resonant operation could be sustaised throughout the 0-600 fps tip speed range. Available thrusts of up to 21% lbs. have been obtained with the 5-1/2 inch diameter engine with thrust specific fuel consumptions somewhat less than 7 lbs. fuel per hour per pound thrust at 600 fps tip speed.